Enhances the contrast of a color image by adjusting the pixels color to span the entire range of colors available
- black_point
- The black point.
- white_point
- The white point.
- channel
-
Provide any channel constant that is valid for your channel mode. To apply to more than one channel, combine channeltype constants using bitwise operators. Defaults to Imagick::CHANNEL_ALL.
- Channel constants:
-
imagick::CHANNEL_UNDEFINED
imagick::CHANNEL_RED
imagick::CHANNEL_GRAY
imagick::CHANNEL_CYAN
imagick::CHANNEL_GREEN
imagick::CHANNEL_MAGENTA
imagick::CHANNEL_BLUE
imagick::CHANNEL_YELLOW
imagick::CHANNEL_ALPHA
imagick::CHANNEL_OPACITY
imagick::CHANNEL_MATTE
imagick::CHANNEL_BLACK
imagick::CHANNEL_INDEX
imagick::CHANNEL_ALL
- Return Values
- No value is returned.
Example
<?php
$image = new Imagick("opossum.jpg");
$image->contraststretchImage( 1, 27 );
header( "Content-Type: image/jpeg" );
echo $image;
?>
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